adblock: update 3.4.1

* enable code to support Turris Omnia forthcoming upstream change
  (new kresd 'keep_cache' option) to preserve kresd DNS cache
* fix a 'status' race condition while the adblock process
  is running in parallel
* various small speed improvements
* rework debug output
* refine blacklist handling
* enable the (empty) blacklist source in the default config
* email notification supports mstmp, even without sendmail symlink
* email notification writes minimal status to log (one-liner)
* LuCI: refine logfile search term
* LuCI: Textarea 'autoscroll down' in logfile view
* LuCI: Left-align blocklist source table plus a more compact design

Signed-off-by: Dirk Brenken <dev@brenken.org>

net/adblock/files/adblock.conf

@@ -31,7 +31,7 @@ config source 'bitcoin'
 	option adb_src_desc 'focus on malicious bitcoin mining sites, infrequent updates, approx. 20 entries'
 
 config source 'blacklist'
-	option enabled '0'
+	option enabled '1'
 	option adb_src '/etc/adblock/adblock.blacklist'
 	option adb_src_rset '\$0~/^([[:alnum:]_-]+\.){1,}[[:alpha:]]+([[:space:]]|$)/{print tolower(\$1)}'
 	option adb_src_desc 'static local domain blacklist, always deny these domains'